Review article: The use of potentially hepatotoxic drugs in patients with liver disease

Alanine aminotransferase cutoffs for the pediatric fatty liver disease: Major impact of the reference population

OBJECTIVES AND STUDY

The often-recommended alanine aminotransferase (ALT) cutoffs (girls 21 U/l, boys 25 U/l) are based on a NHANES cohort. A novel concept of metabolic dysfunction associated steatotic liver disease (MASLD) emphasizes the role of ALT. We tested the prevalence of increased ALT and MASLD in children with overweight or obesity applying population-based and NHANES-based cut-offs.

METHODS

Six- to seventeen-year-old children underwent data collection in a prospective Physical Activity and Nutrition in Children (PANIC) study. ALT 95th percentiles were calculated from 1167 separate measurements considering various confounders. Test cohort comprised 1044 children with overweight/obesity.

RESULTS

ALT values increased at puberty onset (p = 0.031) and correlated negatively with age in girls (r = -0.222, p < 0.001). Particularly overall and central obesity increased ALT, whereas underweight or metabolic abnormalities had smaller effect. After applying the tested exclusions, the age-related ALT 95th percentiles were 24-29 U/l for girls and 29-32 U/l for boys. In 6-8-year-old children with overweight/obesity, the prevalence of increased ALT and MASLD were 21.6% and 2.4% with age-specific PANIC cutoffs. In older children, when NHANES-based cutoffs were used, there was a trend for higher prevalence of increased ALT and MASLD in all age groups for both sexes, reaching significance for increased ALT in 12-16-year-old boys (NHANES 63.5%, 95% confidence interval [CI]: 56.4%-70.0% vs. PANIC 47.1%, 95% CI [40.1%-54.2%]) and 9-11-year-old girls (60.0% [49.4%-69.8%] vs. 31.8% [22.8%-42.3%]), respectively. Increased ALT/MASLD were more common in boys than in girls, and in boys these increased with age, whereas in girls these peaked at age 9-12 years.

CONCLUSION

A reference population impacts on the prevalence of increased ALT and MASLD. Considering this help optimizing screening while avoiding unnecessary investigations and surveillance. The prospective part of this study is registered in clinicaltrials.gov; identifier NCT01803776.

Association between potential supplement-drug interactions and liver diseases in patients with cancer: A large prospective cohort study

BACKGROUND & AIMS

The concurrent use of herbal and dietary supplements and conventional drugs can lead to interactions in patients with cancer, of which hepatotoxicity is one of the most concerning sequelae. This study examined the potential supplement-drug interactions involving the hepatic system, and their associations with documented liver diseases, among patients with cancer in a large population-based cohort in the UK Biobank.

METHODS

Participants diagnosed with cancer and had completed supplement-use assessment after diagnosis were included. Potentially interacting supplement-drug combinations that involved CYP enzymes or increased the risk of hepatotoxicity were identified from four tertiary databases. Liver diseases were identified using ICD-codes K70-77. Log-binomial regression was used to investigate the associations between potentially-interacting supplement-drug combinations and liver diseases documented (1) at any time, and (2) confined to only after the time of supplement-use assessment, adjusting for age, sex and pre-existing comorbidities.

RESULTS

This analysis included 30,239 participants (mean age = 60.0 years; 61.9% female). Over half (n = 17,698, 58.5%) reported the use of supplements after cancer diagnoses. Among supplements users, 36.9% (n = 6537/17,698) were on supplement-drug combinations with interacting potential involving the hepatic system. Patients taking supplements and drugs who had hepatic comorbidities were more likely to take potentially interacting pairs (adjusted risk ratio = 1.14, 95% CI = 1.06-1.23, p < 0.001). However, no significant association was observed between the use of these combinations and subsequent liver diseases (all p > 0.05).

CONCLUSION

Approximately one-third of the participants who had cancer and were supplement users had a risk of potential supplement-drug interactions that contribute to adverse liver effect. Healthcare professionals should communicate with patients with cancer, especially those with pre-existing liver diseases, about supplement use and proactively assess the clinical significance of potential interactions.

Acute Multi-Organ Toxicity During 24-Hour Dosing of Intravenous Amiodarone: A Case Report

We present a unique case of a 60-year-old male with congestive heart failure who was admitted for a pre-syncopal episode and found to be in atrial fibrillation with rapid ventricular response (RVR). In order to effectively rate control the patient, he was administered an amiodarone bolus and intravenous (IV) infusion over 24 hours, along with a single oral 200 mg dose the following day. The patient subsequently developed acute hepatotoxicity along with features of acute kidney injury (AKI), pulmonary distress, and leukocytosis. After ruling out other etiologies for acute liver, pulmonary, and kidney injury, amiodarone-induced multi-organ toxicity was suspected and amiodarone was discontinued. Within hours of amiodarone discontinuation, the patient’s clinical status and organ function improved remarkably. In the setting of a patient being treated with IV amiodarone and presenting with sudden signs of dyspnea, acute elevation of transaminases and AKI within one to two days of initial dosing, acute amiodarone-induced organ toxicity should be considered.

Heat-Killed Enterococcus faecalis EF-2001 Attenuate Lipid Accumulation in Diet-Induced Obese (DIO) Mice by Activating AMPK Signaling in Liver

To explore the inhibitory mechanism of heat-killed Enterococcus faecalis, EF-2001 on hepatic lipid deposition, a diet-induced obese (DIO) animal model was established by high-fat diet (HFD). The DIO C57BL/6 mice were divided into four groups: the normal group without HFD (ND, n = 8), obesity group (HFD, n = 8), experimental group (HFD + EF-2001, 200 mg/kg, n = 8), and positive control group (HFD + Orlistat, 60 mg/kg, n = 8). After 4 weeks, liver and adipose tissue were fixed in 10% paraformaldehyde, followed by embedding in paraffin for tissue sectioning. The differences in body mass, body fat ratio, fatty cell area, and lipid profiling of the liver (TC, LDL, and HDL) were also determined. Moreover, Western blot was performed to analyze the expression of lipid accumulation-related proteins, including AMPK，PPARγ, SREBP-1, ACC, and FAS. Compared with the HFD group, the HFD + EF-2001 group exhibited decreased fat mass, liver index, adipocyte area, TC, and LDL, and an increased level of HDL. The results of liver hematoxylin and eosin (H&E), and oil red O staining showed that the mice in each intervention group were improved on hepatic lipid accumulation, and the mice in the HFD + EF-2001 group were the most similar to those in the normal group when compared with the HFD group. From the Western blot results, we proved that EF-2001 activated the AMPK signaling pathway. EF-2001 significantly upregulated the expressions of p-AMPK and p-ACC and downregulated PPARγ, SREBP-1, and FAS in murine liver. Taken together, these results suggest that EF-2001 decrease lipid accumulation in the DIO model mice through the AMPK pathway and ameliorate liver damage by HFD.

Systematic Review of Antifungal-Induced Acute Liver Failure

Antifungals are effective antimicrobial agents broadly used in medical practice. Severe acute liver failure from oral or IV administration of antifungals is a rare but long-standing clinical challenge. We aimed to approximate the risk of clinical acute liver injury among users of oral antifungals in the general population. This review was completed based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Six articles were included, comprising case reports and cohort studies, after eliminating duplicate publications. No randomized control studies were found. In all studies, the duration of antifungal use was associated with significantly increased liver enzyme levels. Although it is not very common for patients on antifungals to develop acute liver failure, the prognosis is often good with swift discontinuation of the drug and proper treatment. Liver function evaluation before treatment and periodic monitoring every three to six weeks after commencement of treatment is suggested.

Antiviral Therapy for Hepatitis B Prevents Liver Injury in Patients With Tuberculosis and Hepatitis B Coinfection

BACKGROUND

Chronic hepatitis B virus (HBV) infection increases the risk of liver injury in patients who undergo antituberculosis treatment. It is uncertain whether antiviral treatment for HBV at the time of tuberculosis diagnosis would reduce the risk of liver injury.

METHODS

We performed a population-level, retrospective, cohort study that involved all patients with tuberculosis-HBV coinfection treated in public hospitals in Hong Kong over a 16-year period. Patients who received antiviral treatment at the time of tuberculosis diagnosis were considered "patients on antiviral therapy." A multivariable Cox proportional hazards model was used to determine the adjusted hazard ratio of hospitalization due to drug-induced liver injury within 1 year in patients on antiviral therapy, adjusting for the propensity score.

RESULTS

Of 3698 patients with tuberculosis-HBV coinfection, 488 (13.2%) were patients on antiviral therapy. Of the remaining 3210 patients, 446 (13.9%) started antiviral therapy within 1 year of tuberculosis diagnosis. Adjusting for the propensity score, patients on antiviral therapy had a lower risk of hospitalization due to drug-induced liver injury compared with those not on treatment (adjusted hazard ratio, 0.44; 95% confidence interval .26-.72). Compared with patients who started antiviral therapy within 1 year of tuberculosis diagnosis, patients on antiviral therapy also had a lower risk of hospitalization due to drug-induced liver injury and a lower risk of liver-related mortality.

CONCLUSIONS

We show that antiviral treatment for HBV given at the time of tuberculosis diagnosis reduced the risk of liver injury in tuberculosis-HBV coinfected patients.

A retrospective case-controlled cohort study of inpatient drug induced liver injury: the RIDDLE study

Background

Identification of risk factors for drug-induced liver injury (DILI) has been hindered by the unpredictable incidence and idiosyncratic nature of DILI. The aim of this study was to identify characteristic host risk factors for DILI.

Methods

A retrospective cohort study was performed examining all patients admitted with a diagnosis of DILI over a 5.5-year period. Cases were compared to a control group non-exposed to DILI using propensity score-derived inverse probability weights. Patients with DILI due to alcohol or paracetamol were excluded from analysis.

Results

Seventy-two cases of DILI admitted to hospital were identified. Antimicrobials caused 56.9% of cases, with amoxicillin-clavulanate the single most common agent, responsible for 13.9% of cases. DILI cohort median age (50.2±36 years) was significantly younger than controls (65.0±38 years) (P<0.001). Pre-existing chronic liver disease (OR, 3.44; 95% CI, 1.38-8.59; P=0.008), length of stay (P<0.001) and in-hospital death (P=0.009) were more likely to be associated with DILI cases. There was no correlation with sex (OR male, 0.92; 95% CI, 0.50-1.67; P=0.78), presence of comorbid autoimmune disease (OR, 1.44; 95% CI, 0.68-3.05; P=0.35), past drug allergies (OR, 1.71; 95% CI, 0.92-3.16; P=0.09), or atopy (OR, 0.87; 95% CI, 0.42-1.82; P=0.72).

Conclusions

Younger age and presence of chronic liver disease were associated with an admission with DILI; however, it remains difficult to predict the population at risk of DILI on clinical grounds and putative risk factors such as female gender, and history of other drug allergies and autoimmunity, were not demonstrated in this study.

Herbal medicine use among patients with viral and non-viral Hepatitis in Uganda: prevalence, patterns and related factors

Background

There is some evidence that patients with liver diseases commonly use complementary and alternative therapies to address general and liver-disease specific health concerns. The purpose of this study was to assess and describe prevalence, patterns and related factors of herbal medicine use among adults diagnosed with viral and non-viral hepatitis in Kampala, Uganda.

Methods

A cross-sectional study was conducted on 310 adult patients attending the gastrointestinal clinic in Mulago hospital referral hospital in Kampala. Data on prevalence, types and reasons for herbal medicine use was collected using standardized questionnaires and focus group discussions. Modified Poisson regression analyses were used to examine factors related to use.

Results

Usage of various herbal remedies within 12 months prior to April 2018 was reported by 46.1% (143/310) of patients with 27.3% (39/143) of these reporting having used conventional and herbal therapies concurrently. Herbal remedies were used to treat various health conditions including hepatitis. Patients with hepatitis C virus infection (PRR = 1.16, p = 0.02) compared to those with hepatitis B virus infection, and those who believed that it was safe to use herbal and conventional therapies concurrently (PRR = 1.23, p = 0.008) had higher prevalence odds of herbal medicine use. Conversely, patients who had been newly diagnosed with hepatitis (PRR = 0.69, p = 0.03) compared to those who had been diagnosed more than one-year prior, had lower prevalence odds of herbal medicine use. Various types of local herbs were reported as most commonly used however most patients did not know the ingredients of commercially prepared herbal therapies.

Conclusion

A high prevalence of herbal medicine use was found among newly-diagnosed patients and patients with hepatitis C more likely to use herbal remedies after adjusting for other factors. Usage was influenced by the belief that herbal medicine is safe and effective. Health workers need to consistently elicit information about herbal remedy use. Research is needed on benefits, adverse effects and outcomes in patients who use herbal remedies to treat primary liver diseases in order to facilitate evidence of efficacy and product safety.

Chinese Herbal Formula (CHF03) Attenuates Non-Alcoholic Fatty Liver Disease (NAFLD) Through Inhibiting Lipogenesis and Anti-Oxidation Mechanisms

Nonalcoholic fatty liver disease (NAFLD) is a hepatic ailment with a rapidly increasing incidence in the human population due largely to dietary hyper nutrition and subsequent obesity. Discovering effective natural compounds and herbs against NAFLD can provide alternative and complementary medical treatments to current chemical pharmaceuticals. In this study, ICR male mice were fed a high-fat diet (HFD) in vivo and the AML12 cells were treated with palmitic acid (PA) in vitro. We explore the protective effect and potential mechanism of Chinese Herbal Formula (CHF03) against NAFLD by HE staining, transmission Electron Microscopy assay, Western blotting, and gene expression. In vivo, oxidative stress markers (GSH, GSH-px, MDA, SOD, and CAT) confirmed that CHF03 alleviated oxidative stress and abundance of NF-κB proteins indicating a reduction in inflammation and oxidative stress. The lower protein abundance of ACACA and FASN indicated a preventive effect on lipogenesis. Histological and ultrastructural observations revealed that CHF03 inhibited NAFLD. Expression of Srebf1, Fasn, and Acaca, which are associated with lipogenesis, were downregulated. In vitro, genes and proteins are expressed in a dose-dependent manner, consistent with those in the liver. CHF03 inhibited lipid accumulation and expression of NF-κB, nuclear transfer, and transcriptional activity in AML12 cells. The CHF03 might have a beneficial role in the prevention of hepatic steatosis by altering the expression of lipogenic genes and attenuating oxidative stress.

Prescribing in Chronic Severe Hepatic Impairment

Therapeutic Reviews aim to provide essential independent information for health professionals about drugs used in palliative and hospice care. Additional content is available via www.palliativedrugs.com. The series editors welcome feedback on the articles.

Attempts to Limit Opioid Prescribing in Critically Ill Patients: Not So Easy, Not So Fast

OBJECTIVE

To discuss why opioids have been considered the long-standing first-line therapy for treating acute, severe nociceptive pain in critically ill patients and discuss considerations for limiting opioid overuse in the intensive care unit setting.

DATA SOURCES

Articles were identified through searches of PubMed and EMBASE from database inception until December 2018. Additional references were located through a review of the bibliographies of articles and clinical practice guidelines.

STUDY SELECTION AND DATA EXTRACTION

Original research articles excluding case reports were included if they concerned nonopioid agents for pain management in critically ill patients. The focus was on studies not included in the most recent pain management guidelines.

DATA SYNTHESIS

Ten studies were retrieved. Nonopioid therapies or opioid-sparing therapies have been touted as possible alternatives for critically ill patients, but they have particular adverse effects concerns in critically ill patients, often lack parenteral dosage forms, and frequently require dose adjustment or avoidance in patients with renal or hepatic dysfunction. Relevance to Patient Care and Clinical Practice: There is a well-recognized opioid epidemic that has been the subject of much discussion. Attempts to control the epidemic have focused on limiting opioid prescribing and using nonopioid alternatives, but there are special considerations when treating severe pain in critically ill patients that often preclude nonopioid analgesics.

CONCLUSIONS

There continues to be an unmet need for medications that are as effective as opioids for severe nociceptive pain in critically ill patients but without the adverse effect and abuse concerns. Until such medications are available, clinicians need to optimize prescribing of opioid and nonopioid analgesics.

Pre-Existing Liver Disease and Toxicity of Antifungals

Pre-existing liver disease in patients with invasive fungal infections further complicates their management. Altered pharmacokinetics and tolerance issues of antifungal drugs are important concerns. Adjustment of the dosage of antifungal agents in these cases can be challenging given that current evidence to guide decision-making is limited. This comprehensive review aims to evaluate the existing evidence related to antifungal treatment in individuals with liver dysfunction. This article also provides suggestions for dosage adjustment of antifungal drugs in patients with varying degrees of hepatic impairment, after accounting for established or emerging pharmacokinetic–pharmacodynamic relationships with regard to antifungal drug efficacy in vivo.

Incidence of Hepatitis B Virus Reactivation and Hepatotoxicity in Patients Receiving Long-term Treatment With Tumor Necrosis Factor Antagonists

BACKGROUND & AIMS

Tumor necrosis factor (TNF) antagonists are the first-line treatment for many autoimmune diseases. However, they have been associated with reactivation of hepatitis B virus (HBV). We determined the rate of HBV reactivation and hepatotoxicity grade 3 or 4 (HT ≥3) in patients treated with an anti-TNF agent for an autoimmune disease.

METHODS

We collected data from 8887 adult patients in the Kaiser Permanente Northern California database who began treatment with TNF antagonists for autoimmune diseases (dermatologic, rheumatologic, or gastrointestinal) from 2001 through 2010, followed through December 2012. We obtained data on HBV infection (52% of patients were screened for HBV before treatment), demographic features, comorbidities, and use of immunosuppressive agents. HBV reactivation was defined as 1 of the following: >1 log increase in HBV DNA, HBV DNA-positive when previously negative, HBV DNA >2000 IU/mL if no baseline level was available, or reverse seroconversion. HT ≥3 was defined according to the National Cancer Institute Common Toxicity Criteria. We performed multivariable logistic regression to identify factors associated with HT ≥3.

RESULTS

Twenty-three patients tested positive for HB surface antigen (HBsAg) at baseline and 9 of these had HBV reactivation; of the 4267 patients with unknown HBV status at baseline, 2 had HBV reactivation. None of the 178 patients who were HBsAg negative and positive for the hepatitis B core antibody (anti-HBc+) had HBV reactivation. HBV reactivation occurred in 1/5 HBsAg+ patients who received prophylactic antiviral therapy and 8/18 who did not (P = .61). No one with HBV reactivation had liver failure. HT ≥3 occurred in 273 patients (2.7%), but only 3 cases were attributed to HBV. Cirrhosis was significantly associated with HT ≥3 (P < .001).

CONCLUSION

In a retrospective analysis of patients treated with TNF antagonists for autoimmune diseases, we found HBV reactivation in 39% of patients who were HBsAg+ before therapy, but not in any patients who were HBsAg-negative and anti-HBc+ before therapy. Patients should be screened for HBV infection before anti-TNF therapy; HBsAg+ patients should receive prophylactic antiviral therapy, but not HBsAg-negative, anti-HBc+ patients.

Risk of Acute Liver Injury After Statin Initiation by Human Immunodeficiency Virus and Chronic Hepatitis C Virus Infection Status

Background

Patients with human immunodeficiency virus (HIV) and/or chronic hepatitis C virus (HCV) infection may be prescribed statins as treatment for metabolic/cardiovascular disease, but it remains unclear if the risk of acute liver injury (ALI) is increased for statin initiators compared to nonusers in groups classified by HIV/HCV status.

Methods

We conducted a cohort study to compare rates of ALI in statin initiators vs nonusers among 7686 HIV/HCV-coinfected, 8155 HCV-monoinfected, 17739 HIV-monoinfected, and 36604 uninfected persons in the Veterans Aging Cohort Study (2000-2012). We determined development of (1) liver aminotransferases >200 U/L, (2) severe ALI (coagulopathy with hyperbilirubinemia), and (3) death, all within 18 months. Cox regression was used to determine propensity score-adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) of outcomes in statin initiators compared to nonusers across the groups.

Results

Among HIV/HCV-coinfected patients, statin initiators had lower risks of aminotransferase levels >200 U/L (HR, 0.66 [95% CI, .53-.83]), severe ALI (HR, 0.23 [95% CI, .12-.46]), and death (HR, 0.36 [95% CI, .28-.46]) compared with statin nonusers. In the setting of chronic HCV alone, statin initiators had reduced risks of aminotransferase elevations (HR, 0.57 [95% CI, .45-.72]), severe ALI (HR, 0.15 [95% CI, .06-.37]), and death (HR, 0.42 [95% CI, .32-.54]) than nonusers. Among HIV-monoinfected patients, statin initiators had lower risks of aminotransferase increases (HR, 0.52 [95% CI, .40-.66]), severe ALI (HR, 0.26 [95% CI, .13-.55]), and death (HR, 0.19 [95% CI, .16-.23]) compared with nonusers. Results were similar among uninfected persons.

Conclusions

Regardless of HIV and/or chronic HCV status, statin initiators had a lower risk of ALI and death within 18 months compared with statin nonusers.

Exacerbated liver injury of antithyroid drugs in endotoxin-treated mice

Drug-induced liver injury is a major concern in clinical studies as well as in post-marketing surveillance. Previous evidence suggested that drug exposure during periods of inflammation could increase an individual's susceptibility to drug hepatoxicity. The antithyroid drugs, methimazole (MMI) and propylthiouracil (PTU) can cause adverse reactions in patients, with liver as a usual target. We tested the hypothesis that MMI and PTU could be rendered hepatotoxic in animals undergoing a modest inflammation. Mice were treated with a nonhepatotoxic dose of LPS (100 µg/kg, i.p) or its vehicle. Nonhepatotoxic doses of MMI (10, 25 and 50 mg/kg, oral) and PTU (10, 25 and 50 mg/kg, oral) were administered two hours after LPS treatment. It was found that liver injury was evident only in animals received both drug and LPS, as estimated by increases in serum alanine aminotransferase (ALT), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and TNF-α. An increase in liver myeloperoxidase (MPO) enzyme activity and tissue lipid peroxidation (LPO) in addition of liver glutathione (GSH) depletion were also detected in LPS and antithyroid drugs cotreated animals. Furthermore, histopathological changes including, endotheliitis, fatty changes, severe inflammatory cells infiltration (hepatitis) and sinusoidal congestion were detected in liver tissue. Methyl palmitate (2 g/kg, i.v, 44 hours before LPS), as a macrophage suppressor, significantly alleviated antithyroids hepatotoxicity in LPS-treated animals. The results indicate a synergistic liver injury from antithyroid drugs and bacterial lipopolysaccharide coexposure.

A Biomedical Investigation of the Hepatoprotective Effect of Radix salviae miltiorrhizae and Network Pharmacology-Based Prediction of the Active Compounds and Molecular Targets

Radix salviae miltiorrhizae (Danshen in Chinese), a classic traditional Chinese medicine (TCM) herb, has been used for centuries to treat liver diseases. In this study, the preventive and curative potential of Danshen aqueous extract on acute/chronic alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD) was studied. The in vivo results indicated that Danshen could alleviate hepatic inflammation, fatty degeneration, and haptic fibrogenesis in ALD and NAFLD models. In the aspect of mechanism of action, the significant reduction in MDA levels in both ALD and NAFLD models implies the decreased levels of oxidative stress by Danshen. However, Danshen treatment could not activate the internal enzymatic antioxidant system in ALD and NAFLD models. To further explore the hepatoprotective mechanism of Danshen, an in silico-based network pharmacology approach was employed in the present study. The pharmacological network analysis result revealed that six potential active ingredients such as tanshinone iia, salvianolic acid b, and Danshensu may contribute to the hepatoprotective effects of Danshen on ALD and NAFLD. The action mechanism may relate with regulating the intracellular molecular targets such as PPARα, CYP1A2, and MMP2 for regulation of lipid metabolism, antioxidant and anti-fibrogenesis by these potential active ingredients. Our studies suggest that the combination of network pharmacology strategy with in vivo experimental study may provide a forceful tool for exploring the mechanism of action of traditional Chinese medicine (TCM) herb and developing novel bioactive ingredients.

Drug metabolism and liver disease: a drug-gene-environment interaction

Despite the central role of the liver in drug metabolism, surprisingly there is lack of certainty in anticipating the extent of modification of the clearance of a given drug in a given patient. The intent of this review is to provide a conceptual framework in considering the impact of liver disease on drug disposition and reciprocally the impact of drug disposition on liver disease. It is proposed that improved understanding of the situation is gained by considering the issue as a special example of a drug-gene-environment interaction. This requires an integration of knowledge of the drug's properties, knowledge of the gene products involved in its metabolism, and knowledge of the pathophysiology of its disposition. This will enhance the level of predictability of drug disposition and toxicity for a drug of interest in an individual patient. It is our contention that advances in pharmacology, pharmacogenomics, and hepatology, together with concerted interests in the academic, regulatory, and pharmaceutical industry communities provide an ideal immediate environment to move from a qualitative reactive approach to quantitative proactive approach in individualizing patient therapy in liver disease.

Drug-induced liver injury: Is chronic liver disease a risk factor and a clinical issue?

INTRODUCTION

Clinicians and practitioners caring for patients with chronic liver disease are often unsure whether drug therapy is a hazard that increases their patient's risk for drug-induced liver injury (DILI). Areas covered: We searched for reports of drug induced liver injury, both idiosyncratic and intrinsic, in patients with chronic liver disease including non-alcoholic and alcoholic liver disease, and cirrhosis. Reports we analyzed include statin treatment in patients with fatty liver, acetaminophen use in alcoholic fatty liver, antituberculous drugs in patients with tuberculosis and viral hepatitis, antiviral medications in hepatitis and antiretroviral medications in HIV/AIDS. The most challenging cases we found are drug therapy in patients with decompensated liver cirrhosis. Expert opinion: We identified many case reports and case series discussing a potential increased risk of DILI in patients with pre-existing liver disease. However, most of these reports were retrospective and ambiguous. With few exceptions, we conclude that drugs seem to be well tolerated by the majority of patients with pre-existing, non-cirrhotic chronic liver diseases. Special care is needed for some therapies, however, including antiviral therapy in chronic hepatitis B and C and in decompensated liver cirrhosis with impaired drug metabolism. Prospective studies are warranted to valid our conclusions.

The pharmacotherapy of cirrhosis: concerns and proposed investigations and solutions

WHAT IS KNOWN AND OBJECTIVE

The presence of cirrhosis has a multifaceted impact on hepatic drug metabolism. An area of concern and uncertainty in the care of patients with cirrhosis is the safe use of both prescription and over-the-counter medications.

COMMENT

Retrospective studies indicate a high incidence of adverse drug reactions (ADRs) among patients with cirrhosis related to use of certain medication classes including angiotensin-converting enzyme inhibitors, angiotensin receptor blockers and non-steroidal anti-inflammatory drugs. Conversely, use of appropriate medications, such as statins, may be decreased in this population due to fear of precipitating hepatotoxicity.

WHAT IS NEW AND CONCLUSION

Pharmacotherapy in cirrhosis is an area of uncertainty and heterogeneity in clinical practice. Prescribing and dosing guidelines are needed to decrease the risk of serious ADRs in this high-risk patient population.

Oral Azole Antifungal Medications and Risk of Acute Liver Injury, Overall and by Chronic Liver Disease Status

BACKGROUND

Reports on associations between azole antifungal medications and acute liver injury are inconsistent and have not been based on liver-related laboratory tests. We evaluated incidence rates of acute liver injury associated with oral azole antifungals.

METHODS

We conducted a cohort study among Kaiser Permanente Northern California members who initiated an oral azole antifungal in an outpatient setting during 2004-2010. We determined development of: (1) liver aminotransferases >200 U/L, (2) severe acute liver injury (coagulopathy with hyperbilirubinemia), and (3) acute liver failure. We calculated incidence rates of endpoints. Cox regression was used to determine whether chronic liver disease was a risk factor for outcomes.

RESULTS

Among 195,334 azole initiators (178,879 fluconazole; 14,296 ketoconazole; 1653 itraconazole; 478 voriconazole; 28 posaconazole), incidence rates (events/1000 person-years [95% confidence intervals (CIs)]) of liver aminotransferases >200 U/L were similarly low with fluconazole (13.0 [11.4-14.6]), ketoconazole (19.3 [13.8-26.3]), and itraconazole (24.5 [10.6-48.2]). Rates were higher with voriconazole (181.9 [112.6-278.0]) and posaconazole (191.1 [23.1-690.4]), but comparable. Severe acute liver injury was uncommon with fluconazole (2.0 [1.4-2.7]), ketoconazole (2.9 [1.1-6.3]), and itraconazole (0.0 [0.0-11.2]), but more frequent with voriconazole (16.7 [2.0-60.2]) and posaconazole (93.4 [2.4-520.6]). One patient developed acute liver failure due to ketoconazole. Pre-existing chronic liver disease increased risks of aminotransferases >200 U/L (hazard ratio 4.68 [95% CI, 3.68-5.94]) and severe acute liver injury (hazard ratio 5.62 [95% CI, 2.56-12.35]).

CONCLUSIONS

Rates of acute liver injury were similarly low for fluconazole, ketoconazole, and itraconazole. Events were more common among voriconazole and posaconazole users but were comparable. Pre-existing chronic liver disease increased risk of azole-induced liver injury.

Current and future directions in the treatment and prevention of drug-induced liver injury: a systematic review

While the pace of discovery of new agents, mechanisms and risk factors involved in drug-induced liver injury (DILI) remains brisk, advances in the treatment of acute DILI seems slow by comparison. In general, the key to treating suspected DILI is to stop using the drug prior to developing irreversible liver failure. However, predicting when to stop is an inexact science, and commonly used ALT monitoring is an ineffective strategy outside of clinical trials. The only specific antidote for acute DILI remains N-acetylcysteine (NAC) for acetaminophen poisoning, although NAC is proving to be beneficial in some cases of non-acetaminophen DILI in adults. Corticosteroids can be effective for DILI associated with autoimmune or systemic hypersensitivity features. Ursodeoxycholic acid, silymarin and glycyrrhizin have been used to treat DILI for decades, but success remains anecdotal. Bile acid washout regimens using cholestyramine appear to be more evidenced based, in particular for leflunomide toxicity. For drug-induced acute liver failure, the use of liver support systems is still investigational in the United States and emergency liver transplant remains limited by its availability. Primary prevention appears to be the key to avoiding DILI and the need for acute treatment. Pharmacogenomics, including human leukocyte antigen genotyping and the discovery of specific DILI biomarkers offers significant promise for the future. This article describes and summarizes the numerous and diverse treatment and prevention modalities that are currently available to manage DILI.

The Art and Science of Diagnosing and Managing Drug-induced Liver Injury in 2015 and Beyond

Drug-induced liver injury (DILI) remains a leading reason why new compounds are dropped from further study or are the subject of product warnings and regulatory actions. Hy's Law of drug-induced hepatocellular jaundice causing a case-fatality rate or need for transplant of 10% or higher has been validated in several large national registries, including the ongoing, prospective U.S. Drug-Induced Liver Injury Network. It serves as the basis for stopping rules in clinical trials and in clinical practice. Because DILI can mimic all known causes of acute and chronic liver disease, establishing causality can be difficult. Histopathologic findings are often nonspecific and rarely, if ever, considered pathognomonic. A daily drug dose >50-100 mg is more likely to be hepatotoxic than does <10 mg, especially if the compound is highly lipophilic or undergoes extensive hepatic metabolism. The quest for a predictive biomarker to replace alanine aminotransferase is ongoing. Markers of necrosis and apoptosis such as microRNA-122 and keratin 18 may prove useful in identifying patients at risk for severe injury when they initially present with a suspected acetaminophen overdose. Although a number of drugs causing idiosyncratic DILI have HLA associations that may allow for pre-prescription testing to prevent hepatotoxicity, the cost and relatively low frequency of injury among affected patients limit the current usefulness of such genome-wide association studies. Alanine aminotransferase monitoring is often recommended but has rarely been shown to be an effective method to prevent serious DILI. Guidelines on the diagnosis and management of DILI have recently been published, although specific therapies remain limited. The LiverTox Web site has been introduced as an interactive online virtual textbook that makes the latest information on more than 650 agents available to clinicians, regulators, and drug developers alike.

Drug Induced Liver Injury: Review with a Focus on Genetic Factors, Tissue Diagnosis, and Treatment Options

Drug-induced liver injury (DILI) is a rare but potentially life threatening adverse drug reaction. DILI may mimic any morphologic characteristic of acute or chronic liver disease, and the histopathologic features of DILI may be indistinguishable from those of other causes of liver injury, such as acute viral hepatitis. In this review article, we provide an update on causative agents, clinical features, pathogenesis, diagnosis modalities, and outcomes of DILI. In addition, we review results of recently reported genetic studies and updates on pharmacological and invasive treatments.

Sesamol reduces the atherogenicity of electronegative L5 LDL in vivo and in vitro

Highly electronegative low-density lipoprotein (LDL) L5 induces endothelial cell (EC) apoptosis, which leads to the development of atherosclerosis. We examined the effects of sesamol (1), a natural organic component of sesame oil, on plasma L5 levels and atherosclerosis development in a rodent model and on the L5-induced apoptosis of ECs. Syrian hamsters, which have an LDL profile similar to that of humans, were fed a normal chow diet (control), a high-fat diet (HFD), or a HFD supplemented with the administration of 50 or 100 mg/kg of 1 via oral gavage (HFD+1) for 16 weeks (n = 8 per group). Hamsters in the HFD+1 groups had reduced plasma L5 levels when compared with the HFD group. Oil Red O staining showed that atherosclerotic lesion size was markedly reduced in the aortic arch of hamsters in the HFD+1 groups when compared with that in the HFD group. In human aortic ECs, 0.3-3 μM 1 blocked L5-induced apoptosis in a dose-dependent manner. Further mechanistic studies showed that 1 inhibited the L5-induced lectin-like oxidized LDL receptor-1 (LOX-1)-dependent phosphorylation of p38 MAPK and activation of caspase-3 and increased phosphorylation of eNOS and Akt. Our findings suggest that sesamol (1) protects against atherosclerosis by reducing L5-induced atherogenicity.

Profiling cumulative proportional reporting ratios of drug-induced liver injury in the FDA Adverse Event Reporting System (FAERS) database

BACKGROUND

Early prediction and accurate characterization of risk for serious liver injury associated with newly marketed drugs remains an important challenge for clinicians, the pharmaceutical industry, and regulators. To date, a biomarker that specifically indicates exposure to a drug as the etiologic cause of liver injury has not been identified.

OBJECTIVES

Using cumulative proportional reporting ratios (PRRs), we investigated 'real-time' profiles of a set of pharmaceuticals, over the first 3 years of US marketing, for the signaling of clinically serious drug-induced liver injury (DILI) in a large spontaneous-reporting database.

METHODS

Using report counts of hepatic failure or clinically serious liver injury obtained from the FDA Adverse Events Reporting System (FAERS) database, PRRs of adverse drug event terms were calculated by division of counts of domestic reports of these events by counts of all serious adverse events for each of 13 selected drugs associated with a broad range of hepatotoxic risk (including three linked to only rare instances of clinically apparent liver injury) with reference to all other drugs in the database. Drug-specific cumulative PRRs were measured at successive intervals (calendar quarters) using cumulative tallies of FAERS reports to generate time-based profiles over the initial 3 years of US marketing.

RESULTS

In the set of drugs analyzed, those with no known hepatotoxic risk demonstrated time-based cumulative PRR profiles that approximate the background rates of hepatic failure and serious liver injury reported in the entire FAERS database. In contrast, those that were removed from marketing or subjected to marketing restrictions due to their potential to cause liver injury were associated with profiles of rapidly rising cumulative PRRs that were greater than 5 within the first 10 million domestic prescriptions or the first four quarters of US marketing. The systematic tracking and identification of rising PRRs for DILI associated with newly marketed pharmaceutical and biological agents is a valuable tool for identification of safety signals within the FAERS database.

LIMITATIONS

Disproportionality profiling of spontaneous reports in FAERS (e.g., cumulative PRR measurements), which signals an association between a recently marketed drug and liver injury, is not a method to quantitatively measure drug-related risk. Regulatory actions in response to emerging drug safety concerns often depend on an accurate assessment of risks using multiple sources of data and the consideration of overall benefits and risks of the agent. Causality must be determined through analysis of individual cases to exclude other etiologies of liver injury.

CONCLUSION

The FAERS database can be used to advance empiric hepatotoxicity time-trending reporting levels for newly marketed agents in order to rapidly identify recently launched potential hepatotoxic agents and initiate further evaluation.

Medication prescribing in liver dysfunction

Patients with mental illness often have co-occurring substance abuse which increases the risk for developing cirrhosis, particularly with common etiologies such as hepatitis and alcoholic liver disease. As such, knowledge of how the disease may impact medication prescribing is important. Unfortunately, there is a paucity of data to guide medication prescribing in these patients. Product labeling information should be used in the clinical decision making process. Additionally, clinicians should consider the etiology of disease, adverse effect profile, and pharmacokinetic parameters including solubility, product formulation, protein binding, hydrophilicity, metabolism, bioavailability, extraction ratios, excretion route, and half-life. Thoughtful consideration should be given when prescribing potentially hepatotoxic medications, and those which may increase bleeding risk in patients with coagulopathy. It is essential to ensure every medication has an appropriate indication and carefully evaluate the need for each medication. Overall, more research is necessary to support clinical decision-making with outcomes based research in patients with chronic liver disease.

Drug-induced liver injury: what was new in 2013?

INTRODUCTION

The year 2013 continued to highlight numerous aspects of drug-induced liver injury (DILI), with new information communicated via > 1500 publications. New reports of DILI were described and FDA warnings and alerts were issued for a number of products, emphasizing the risks related to hepatotoxicity.

AREAS COVERED

We provide a summary of the year's published reports of new causes of DILI, along with reviews and reports of established hepatotoxins, new and expanded DILI registries and the continuing emphasis placed on genetic and other risk factors. Several new analyses of data generated from the US DILI Network are included.

EXPERT OPINION

The clinical usefulness of pharmacogenetic testing remains to be determined; the number of patients who must be tested is large and the overall risk of DILI is quite small. The role that dose and hepatic metabolism play in causing idiosyncratic DILI was reviewed; daily doses > 50 - 100 mg of medications with high lipophilicity appear to be most predictive of severe DILI, but not in all cases. Restricting access to paracetamol in certain parts of the UK continues to demonstrate a successful reduction in the number of acute liver failure cases and patients listed for liver transplant.

Construction and analysis of a human hepatotoxicity database suitable for QSAR modeling using post-market safety data

Drug-induced liver injury (DILI) is one of the most common drug-induced adverse events (AEs) leading to life-threatening conditions such as acute liver failure. It has also been recognized as the single most common cause of safety-related post-market withdrawals or warnings. Efforts to develop new predictive methods to assess the likelihood of a drug being a hepatotoxicant have been challenging due to the complexity and idiosyncrasy of clinical manifestations of DILI. The FDA adverse event reporting system (AERS) contains post-market data that depict the morbidity of AEs. Here, we developed a scalable approach to construct a hepatotoxicity database using post-market data for the purpose of quantitative structure-activity relationship (QSAR) modeling. A set of 2029 unique and modelable drug entities with 13,555 drug-AE combinations was extracted from the AERS database using 37 hepatotoxicity-related query preferred terms (PTs). In order to determine the optimal classification scheme to partition positive from negative drugs, a manually-curated DILI calibration set composed of 105 negatives and 177 positives was developed based on the published literature. The final classification scheme combines hepatotoxicity-related PT data with supporting information that optimize the predictive performance across the calibration set. Data for other toxicological endpoints related to liver injury such as liver enzyme abnormalities, cholestasis, and bile duct disorders, were also extracted and classified. Collectively, these datasets can be used to generate a battery of QSAR models that assess a drug's potential to cause DILI.

Complementary and alternative medications in hepatitis C infection

Chronic hepatitis C (CHC) infection affects almost 3% of the global population and can lead to cirrhosis, liver failure, and hepatocellular carcinoma in a significant number of those infected. Until recently, the only treatments available were pegylated interferon and ribavirin, which traditionally were not very effective and have considerable side effects. For this reason, interest in complementary and alternative medications (CAM) in the management of hepatitis C has been investigated. Some CAM has demonstrated therapeutic potential in chronic hepatitis C treatment. Unfortunately, some CAM has been shown to have the potential to cause drug-induced liver injury. This article will review and evaluate many of the natural molecules that interact with the hepatitis C virus (HCV) life cycle and discuss their potential use and safety in HCV therapy, as well as highlight some important interactions between medical and complementary treatments.

Hepatotoxicity of antibiotics: a review and update for the clinician

Collectively, the various classes of antibiotics are a leading cause of drug-induced liver injury (DILI). However, acute antibiotic-associated DILI can be difficult to diagnose, as the course of therapy is usually brief, and other confounding factors are often present. In addition to the broad clinicopathologic spectrum of hepatotoxicity associated with the antimicrobials, the underlying infectious disease being treated may itself be associated with hepatic dysfunction and jaundice. This review provides summarized information on several classes of antimicrobial agents, highlighting new agents causing DILI and updating information on older agents.

Hepatotoxicity and drug interactions in liver transplant candidates and recipients

In this article the medications that have been shown to increase rates of drug-induced liver injury in patients with cirrhosis and the important drug-drug interactions in recipients of liver transplantation are reviewed. In general, the risk of drug-induced liver injury in patients with cirrhosis does not seem to be higher when compared with the noncirrhotic population. There are, however, 2 classes of agents that have been implicated-medications used to treat tuberculosis and medications used to treat human immunodeficiency virus infection. However, with careful monitoring, even significant interactions can be effectively managed.

Review article: prescribing medications in patients with cirrhosis - a practical guide

BACKGROUND

Most drugs have not been well studied in cirrhosis; recommendations on safe use are based largely on experience and/or expert opinion, with dosing recommendations often based on pharmacokinetic (PK) changes.

AIM

To provide a practical approach to prescribing medications for cirrhotic patients.

METHODS

An indexed MEDLINE search was conducted using keywords cirrhosis, drug-induced liver injury, pharmacodynamics (PDs), PKs, drug disposition and adverse drug reactions. Unpublished information from the Food and Drug Administration and industry was also reviewed.

RESULTS

Most medications have not been adequately studied in cirrhosis, and specific prescribing information is often lacking. Lower doses are generally recommended based on PK changes, but data are limited in terms of correlating PD effects with the degree of liver impairment. Very few drugs have been documented to have their hepatotoxicity potential enhanced by cirrhosis; most of these involve antituberculosis or antiretroviral agents used for HIV or viral hepatitis. Paracetamol can be used safely when prescribed in relatively small doses (2-3 g or less/day) for short durations, and is recommended as first-line treatment of pain. In contrast, NSAIDs should be used cautiously (or not at all) in advanced cirrhosis. Proton pump inhibitors have been linked to an increased risk of spontaneous bacterial peritonitis (SBP) in cirrhosis and should be used with care.

CONCLUSIONS

Most drugs can be used safely in cirrhosis, including those that are potentially hepatotoxic, but lower doses or reduced dosing frequency is often recommended, due to altered PKs. Drugs that can precipitate renal failure, gastrointestinal bleeding, SBP and encephalopathy should be identified and avoided.

Incidence of potential drug interactions in medication prescriptions for children and adolescents in the University Hospital Olomouc, Czech Republic

Drug interactions are important potential causes of adverse drug reactions. However, studies of their occurrence in children are almost entirely lacking. This study evaluates the incidence of potential drug interactions (PDIs) in medication prescriptions for children. The study was performed at the University Hospital in Olomouc. PDIs in each patient's prescriptions were identified. Multivariate analysis was performed in order to assess the risk factors confounding the potential interactions. Univariate analysis was used to assess which diagnostic groups and medication groups significantly increase or lower the odds of a potential drug-drug interaction. A total of 6,078 patients meeting the inclusion criteria entered the study. They received 19,522 prescriptions. PDIs were identified in 3.83 % of patients (moderate-to-severe cases in 0.47 %). Patient age (p = 0.008), the average number of prescriptions per visit (p < 0.0001), and the number of visits per year (p < 0.0001) were found to increase the risk of drug interaction. The presence of epilepsy, leukemia, or rheumatoid arthritis and related disease diagnoses were discovered to increase the risk of PDIs significantly.

CONCLUSION

The risk of PDIs in children is low, but it increases significantly with age and the number of drugs prescribed, particularly antiepileptics and immunosuppressants. The finding of a potential interaction in 0.47 % of all children in whom any medication was prescribed should not be underestimated since it means a significant risk for one child out of every 200, and it is also substantially higher in the chronically ill. Pediatricians should be aware of relevant interactions and should prevent them by therapeutic drug monitoring or appropriate clinical and laboratory monitoring.

Current challenges and controversies in drug-induced liver injury

Current key challenges and controversies encountered in the identification of potentially hepatotoxic drugs and the assessment of drug-induced liver injury (DILI) are covered in this article. There is substantial debate over the classification of DILI itself, including the definition and validity of terms such as 'intrinsic' and 'idiosyncratic'. So-called idiosyncratic DILI is typically rare and requires one or more susceptibility factors in individuals. Consequently, it has been difficult to reproduce in animal models, which has limited the understanding of its underlying mechanisms despite numerous hypotheses. Advances in predictive models would also help to enable preclinical elimination of drug candidates and development of novel biomarkers. A small number of liver laboratory tests have been routinely used to help identify DILI, but their interpretation can be limited and confounded by multiple factors. Improved preclinical and clinical biomarkers are therefore needed to accurately detect early signals of liver injury, distinguish drug hepatotoxicity from other forms of liver injury, and differentiate mild from clinically important liver injury. A range of potentially useful biomarkers are emerging, although so far most have only been used preclinically, with only a few validated and used in the clinic for specific circumstances. Advances in the development of genomic biomarkers will improve the prediction and detection of hepatic injury in future. Establishing a definitive clinical diagnosis of DILI can be difficult, since it is based on circumstantial evidence by excluding other aetiologies and, when possible, identifying a drug-specific signature. DILI signals based on standard liver test abnormalities may be affected by underlying diseases such as hepatitis B and C, HIV and cancer, as well as the concomitant use of hepatotoxic drugs to treat some of these conditions. Therefore, a modified approach to DILI assessment is justified in these special populations and a suggested framework is presented that takes into account underlying disease when evaluating DILI signals in individuals. Detection of idiosyncratic DILI should, in some respects, be easier in the postmarketing setting compared with the clinical development programme, since there is a much larger and more varied patient population exposure over longer timeframes. However, postmarketing safety surveillance is currently limited by the quantity and quality of information available to make an accurate diagnosis, the lack of a control group and the rarity of cases. The pooling of multiple healthcare databases, which could potentially contain different types of patient data, is advised to address some of these deficiencies.

Drug-induced liver injury: the role of drug metabolism and transport

Many studies have pinpointed the significant contribution of liver-mediated drug metabolism and transport to the complexity of drug-induced liver injury (DILI). Phase I cytochrome P450 (CYP450) enzymes can lead to altered drug metabolism and formation of toxic metabolites, whilst Phase II enzymes are also associated with DILI. The emerging role of hepatic transporters in regulating the movement of endogenous and exogenous chemicals (e.g., bile acids and drugs) across cellular and tissue membranes is critical in determining the pathophysiology of liver disease as well as drug toxicity and efficacy. Genetic and environmental factors can have a significant impact on drug metabolism and transporter proteins, consequently increasing the risk of DILI in susceptible individuals. The assessment of these factors therefore represents an important approach for predicting and preventing DILI, by better understanding the pharmacological profile of a specific drug. This review focuses on the mechanisms of DILI associated with drug metabolism and hepatic transport, and how they can be influenced by underlying factors.

Drug-induced liver disease

Drug-induced liver injury (DILI), also known as hepatotoxicity, refers to liver injury caused by drugs or other chemical agents, and represents a special type of adverse drug reaction. It has been estimated that more than 600 drugs and chemicals have been associated with significant liver injury. Many previous reviews have focused on DILI pathogenesis or have outlined the clinical features of liver injury linked to different drugs. This article briefly touches on several areas that are potentially vexing for both the novice and cognoscenti, with the goal of guiding the consultant through one of the most challenging areas of hepatology.

Antituberculosis drugs: drug interactions, adverse effects, and use in special situations. Part 1: first-line drugs

The main objectives of tuberculosis therapy are to cure the patients and to minimize the possibility of transmission of the bacillus to healthy subjects. Adverse effects of antituberculosis drugs or drug interactions (among antituberculosis drugs or between antituberculosis drugs and other drugs) can make it necessary to modify or discontinue treatment. We briefly review the new guidelines for the pharmacological treatment of tuberculosis, introduced by the Brazilian National Ministry of Health in 2009, and describe the general mechanism of action, absorption, metabolization, and excretion of the first-line drugs used in the basic regimen. We describe adverse drug reactions and interactions (with other drugs, food, and antacids), as well as the most appropriate approach to special situations, such as pregnancy, breastfeeding, liver failure, and kidney failure. We also describe the mechanisms by which the interactions among the antituberculosis drugs used in the basic regimen can cause drug-induced hepatitis, and we discuss the alternatives in this situation.

Acute-on-chronic liver failure: concept, natural history, and prognosis

PURPOSE OF REVIEW

A population of patients with previously compensated cirrhosis will develop acute deterioration resulting in multiorgan failure and high short-term mortality. Complications of cirrhosis frequently culminate in admissions to the ICU. This review advances the concept of acute-on-chronic liver failure as a distinct clinical entity.

RECENT FINDINGS

Recently, the American Association for the Study of Liver Disease and the European Association for the Study of the Liver created a research consortium to advance the state of the science of acute-on-chronic liver failure. The goal of this consortium is aimed at improving outcomes, identification of a subset of patients with cirrhosis at high risk for deterioration, and the inciting events that lead to this deterioration. Liver transplant remains the only curative option for advanced cirrhosis; however, the limited number of available organs necessitates innovations in the care of advanced liver disease. Liver replacement therapies have not as yet demonstrated reduction in mortality, but have demonstrated improvements in other measures. Large-scale prospective studies of cirrhosis are required.

SUMMARY

Acute-on-chronic liver failure may be a distinct clinical entity with a potential for reversibility when identified early and managed with aggressive critical care support.

Drug-induced liver injury: a summary of recent advances

INTRODUCTION

The knowledge base of drug-induced liver injury (DILI) continues to grow each year as additional drugs are identified as hepatotoxins. There is still a need to improve our ability to predict and diagnose DILI in the preclinical and post-approval settings.

AREAS COVERED

This article presents the new and updated DILI registries for 2010, including the latest information on the causes and outcomes of non-acetaminophen DILI cases in the US Acute Liver Failure Study Group database. As DILI is still largely a diagnosis of exclusion, it is appropriate that causality assessment instruments are again the subject of considerable discussion.

EXPERT OPINION

DILI research remains extremely active including studies aimed at being better able to identify causative agents, utilize potential biomarkers, predict who is at greatest risk of injury and manage outcomes. With respect to identifying DILI risk factors at the genetic level, the field is rapidly approaching the day where 'personalized medicine' (based on pharmacogenomics) will become a reality. A large single-center series from India reminds us that geography can influence the drugs responsible for liver injury; however, Hy's law remains universal. As our DILI knowledge continues to grow, it remains essential to keep abreast of the important changes reported each year.

Predicting and preventing acute drug-induced liver injury: what's new in 2010?

IMPORTANCE OF THE FIELD

The field of drug-induced liver injury (DILI) continues to expand in terms of global registries and with new agents added every year. Given the need to improve on our current methods of preclinical testing and monitoring for DILI during both clinical trials and in the post-approval setting, there is increasing research aimed at better understanding why injury occurs and who is most susceptible. To this end, the active pursuit of biomarkers that will predict injury prior to its occurrence and genetic testing that can identify individuals at risk of DILI continue to be at the forefront.

AREAS COVERED IN THIS REVIEW

While alanine aminotransferase (ALT) testing remains the workhorse of biochemical monitoring, it only detects hepatic injury after it has occurred and, therefore, is not a true predictor. The utility and shortcomings of ALT and other liver tests are reviewed along with a synopsis of several other candidate biomarkers that are being studied. In addition, we review the recent data supporting testing for genetic predisposition to DILI and how identifying clinical risk factors may translate into better means for preventing DILI.

WHAT THE READER WILL GAIN

We update the basis on which age and gender are considered risk factors for DILI, and review the latest reports detailing the association of several candidate genes and the development of DILI in a susceptible patient. Human leukocyte antigen-B*5701 is closely linked to the hypersensitivity reaction seen with abacavir, and such screening has been successfully incorporated into HIV treatment around the globe and offers the promise that testing for other genetic markers will soon become a routine part of clinical practice. At present, candidate genes conferring specific susceptibility to DILI have been identified for a relatively few agents (e.g., flucloxacillin, amoxicillin-clavulanate, ximelagatran and isoniazid), but many more are under study. Preventing DILI often comes down to avoiding the use of potentially hepatotoxic drugs in certain situations, and we review the clinical scenarios in which this is most relevant.

TAKE HOME MESSAGE

Given the number and range of studies aimed at identifying predictors of DILI, the focus of this review is to summarize what we consider to be the most relevant new information published on the topics of clinical and genetic factors that predispose to DILI, the use of biomarkers as predictors of acute DILI, along with advances in prevention strategies.

A fourth dimension in decision making in hepatology

Today, the assessment of liver function in patients suffering from acute or chronic liver disease is based on liver biopsy and blood tests including synthetic function, liver enzymes and viral load, most of which provide only circumstantial evidence as to the degree of hepatic impairment. Most of these tests lack the degree of sensitivity to be useful for follow-up of these patients at the frequency that is needed for decision making in clinical hepatology. Accurate assessment of liver function is essential to determine both short- and long-term prognosis, and for making decisions about liver and non-liver surgery, TIPS, chemoembolization or radiofrequency ablation in patients with chronic liver disease. Liver function tests can serve as the basis for accurate decision-making regarding the need for liver transplantation in the setting of acute failure or in patients with chronic liver disease. The liver metabolic breath test relies on measuring exhaled (13) C tagged methacetin, which is metabolized only by the liver. Measuring this liver-specific substrate by means of molecular correlation spectroscopy is a rapid, non-invasive method for assessing liver function at the point-of-care. The (13) C methacetin breath test (MBT) is a powerful tool to aid clinical hepatologists in bedside decision-making. Our recent findings regarding the ability of point-of-care (13) C MBT to assess the hepatic functional reserve in patients with acute and chronic liver disease are reviewed along with suggested treatment algorithms for common liver disorders.

Hepatotoxicity fears contribute to underutilization of statin medications by primary care physicians

INTRODUCTION

The safety and efficacy of hydroxymethylglutaryl CoA reductase inhibitors (statins) have been extensively demonstrated, but in clinical practice, there remains significant underutilization of these medications. The authors hypothesized that this underutilization could stem in part from fear of liver damage caused by statins. The purpose was to determine whether concern about hepatotoxicity acts as a barrier among primary care physicians to prescribing statins for patients with elevated liver transaminase values and/or underlying liver disease.

METHOD

The survey included 937 primary care physicians from 138 academic centers in the United States, and the following were measured: (1) comparison of statin prescribing for patients with clinical indications and (a) no mention of liver transaminase values, (b) elevated liver transaminase values and (c) underlying liver disease; (2) correlation between perception of statin hepatotoxicity and statin prescribing.

RESULTS

Seventy-one percent of respondents would prescribe statins in scenario 1, (45-year-old woman with low-density lipoprotein 240 mg/dL), whereas only 50% would prescribe statins if the baseline liver transaminase values were elevated to 1.5 times upper limit of normal (P < 0.001). This prescribing rate dropped even further to 40% in scenario 3 (55-year-old man with known coronary disease, low-density lipoprotein 250 mg/dL and hepatitis C). Thirty-seven percent of respondents had falsely elevated perceptions of statin hepatotoxicity risk, and these perceptions correlated inversely with statin prescribing. The method of survey administration prevented calculation of response rate, possibility of response bias exists.

CONCLUSION

Despite extensive data documenting safety of statins, primary care physicians harbor significant hepatotoxicity concerns, and these concerns act as a barrier to statin utilization.

Antituberculosis drug-induced liver injury in chronic hepatitis and cirrhosis

OBJECTIVES

To evaluate the incidence, risk factors and outcomes for anti-tuberculosis (TB) drug-induced liver injury (DILI) in patients with chronic liver disease including cirrhosis.

METHODS

A total of 107 patients with chronic liver disease were assessed for anti-TB DILI. Anti-TB DILI was defined as elevation of alkaline phosphatase (ALP), aspartate transaminase, or alanine transaminase, or an increase in Child-Turcotte-Pugh score within 2 months of initiating anti-TB medication. The risk factors for anti-TB DILI were evaluated by multivariate logistic regression analysis.

RESULTS

Fifty-eight (54%) patients had cirrhosis. Of 93 patients receiving one or more hepatotoxic anti-TB drugs, 18 (17%) experienced DILI: 11 (24%) among 46 patients with chronic hepatitis and 7 (15%) among 46 patients with compensated liver cirrhosis (P = 0.271). Independent risk factors for DILI were female sex, number of hepatotoxic anti-TB drugs administered and baseline ALP levels but not cirrhosis itself. Of the 18 patients with DILI, 13 (72%) successfully completed anti-TB treatment after switching to less hepatotoxic drug regimens.

CONCLUSIONS

Hepatotoxic anti-TB drugs may be safely used in the patients with chronic liver disease including compensated cirrhosis if number of hepatotoxic drugs used is adjusted appropriately.